I have an Ultra Gauge, which is similar. It offers several pages of screens if desired. I'm assuming the Scangauge does too. The basic format is six readings per page. Two are big, the other four are smaller.
My main page, going from memory:
Instant MPG
RPM (I don't have a tach)
Avg MPG
% throttle
Gals remaining
Distance to Empty
My second page is more specifically devoted to MPG
Instant MPG
Avg MPG
Gallons per hour
% load
can't recall the other two
Page 3 is a set of trip figures, resettable:
Avg MPG
Avg speed
Avg GPH
Miles
Gallons used
something else
Page 4 is a a duplicate of page 3, but for "short trip", which means during the current run cycle only.
I have not calibrated it yet. So far it registers about 3% fewer miles than my trip odometer, and likewise lower MPG than my hand calculations. I can calibrate the miles on it using mile posts, and calibrate something else too. I'm sorry I can't recall all this today, I'm worn out.
:)
I will add, so far I don't know that it helped me gain any MPG. The instant reading varies so rapidly that I find it hard to have a feel for it. I wish they offered a smoothed instant MPG reading as an option.